The factor for release of the human growth hormone, also called somatocrinin, hereinafter designated by the abbreviation "GRF", is a positive regulator for the secretion of growth hormone, hereinafter designated by the abbreviation "GH". GRF is a polypeptide of 44 amino acids which has been sequenced and is isolated from a human pancreatic tumor causing acromeagaly. Antibodies against this peptide have enabled identification of an immunoreactive material in the hypothalamus of various primates; moreover, an apparently identical polypeptide has been isolated from the human hypothalamus. Finally, experiments of the "southern blot" type indicate that there is only a single gene coding for GRF. This, therefore, suggests that the tumoral pancreatic factor is coded by the same mRNA as the physiological hypothalamic factor. The usefulness of being able to produce abundant quantities of human GRF is due in particular to the fact that its genetic or physiological deficiency is a cause of dwarfism; that its stimulating effect on the synthesis of GH should lead to its usefulness in diagnosis of deficiencies or disorders of GH metabolism; that its administration could provide an acceleration in regeneration of tissues, for example, in the treatment of severe burn victims; and that it has been shown that the administration of human GRF to animals stimulates their growth.